the cytotoxicity assessment of grapefruit peel essential oil and its effect on frying stability of sunflower oil

Background: frying oil lipids are prone to oxidation, so aromatic plants and their essential oils (eos) have been applied to prevent this process. this study aimed to incorporate the grapefruit (citrus x paradisi) eo in sunflower frying oil to protect it against oxidation. before enrichment, a cytotoxicity test was performed to determine the non-cytotoxic concentration of this eo.methods: cell viability was evaluated using the mtt-based cytotoxicity assay. various eo concentrations (0.01-0.5 mg/ml) were added to cultured cells human umbilical vein endothelial cells (huvecs) and human stellar hepatic cell lines lx-2 (scc064) and incubated for 24 and 48 h. the stability of sunflower oil during frying was assessed by determining several parameters including peroxide value, polar compounds, and free fatty acids. results: the obtained ic50 values after 24 h were 0.276 and 0.200 mg/ml for lx-2 and huvecs cells, respectively, and the results after 48 h were 0.269 and, 0.216 mg/ml, respectively. following that, the appropriate concentration of eo was incorporated into the sunflower oil. an oxidation acceleration test demonstrated that the lowest concentration of eo provided the best oxidation resistance (14 h 59 min) comparatively to the unfortified sunflower oil (11 h 63 min). the stability of enriched oil polar compounds during repeated frying was also noticed. conclusion: the incorporation of this eo into sunflower oil during a deep-frying process led to a significant increase in its oxidative stability; therefore, it can be used as a food additive.